Jacobs School Physician Advises How to Stay Safe During the Coming Deep Freeze

Anyone who is outside in frigid temperatures for more than about 15–30 minutes is at high risk of developing hypothermia, where the body loses heat faster than it can produce it, and frostbite, where the water inside our skin cells can freeze, potentially resulting in permanent tissue damage. Frostbite can be limb-threatening and hypothermia can be life-threatening. Therefore, it’s important to prevent this by limiting outdoor exposure in sub-freezing temperatures and covering all parts of the body with warm layers.

Wool socks and wool gloves/mittens are especially important, as wool insulates really well, even when wet, unlike cotton and other fabrics.

Being cold causes blood vessels to constrict to conserve body heat, causing an increase in blood pressure and heart rate. This, in turn, forces your heart to work hard to pump your blood against higher resistance due to the narrower blood vessels. This is why cold weather increases the risk of heart attacks, especially with exertion like shoveling snow.

• Older adults (70+ years old). 
• Infants and young children.
• Anyone with significant heart or lung diseases, such as heart failure, coronary artery disease, chronic obstructive pulmonary disease (COPD) and asthma. The cold air causes the airways in the lungs to constrict, which makes it harder to breathe and can cause exacerbations of COPD or asthma.
• Anyone with confusion or decreased cognition (such as dementia, delirium, developmental delays, etc.). In an attempt to maintain core temperature, a body that is freezing may divert energy and blood flow away from the brain. This slows down the conduction of neurons through the nervous system, reducing cognitive function, decreasing memory and increasing confusion. This may cause people to make harmful decisions when outside in cold weather, such as taking jackets off and wandering outside rather than seeking shelter. Because of reduced memory, these people are at risk of easily getting lost outside, unable to find their way home.

It’s important to understand that even someone with normal baseline cognitive function can become confused if they become very cold.

This depends on how cold it is, what the wind chill factor is and how warmly dressed you are. In general, though, if the temperature with wind chill factor is 0°F, then time outside should be less than 15-30 minutes maximum. If the temp with wind chill is -20°F or colder, then time outside should be no longer than 5-10 minutes.

• Dress in layers, covering all skin, including face (except eyes) in order to prevent frostbite.
• Push snow, don’t lift it. If the snow has to be lifted periodically, then lift small amounts at a time. You want to minimize exertion as much as possible to decrease the risk of heart attacks and other problems.
• Take frequent breaks as needed.
• Drink lots of fluids before and after shoveling.
• Avoid smoking.

Young kids can get cold and hypothermia much easier than adolescents and adults. Therefore, kids should dress extra warmly in layers and minimize their time outside to less than 30 minutes. If the temperature with wind chill factor is below 0°F, then kids should not be playing outside.

Obviously, it’s best to stay inside as much as possible and not drive during snowstorms and sub-freezing temperatures. However, that may not be possible due to the need to get to work and buy groceries. Therefore, be prepared for dangerous cold weather scenarios by including the following items in your car:

• Good quality snow brush/ice scraper.
• Blankets.
• Extra mittens, hat, scarf.
• Shovel, with a metal blade — not plastic — to shovel snow and break up ice if needed.